DMAC/internal/pkg/server/reactorcoordinator.go

package server

import (
    "fmt"
    "time"
    "context"
    "google.golang.org/grpc"
    "google.golang.org/grpc/credentials/insecure"
    pb "FRMS/internal/pkg/grpc"
)

// this package will implement a reactor coordinator and associated go routines

type ReactorCoordinator struct {
    Server *ReactorListener // embedding parent listener to call methods
    Ip string
    Port int
    Id uint32
    Model string
    MaxAttempts int
}

func NewReactorCoordinator(s *ReactorListener, ip, model string, port int, id uint32) *ReactorCoordinator {
    return &ReactorCoordinator{Server: s, Ip: ip, Port: port, Id: id, Model: model,MaxAttempts:3}
}

func(r *ReactorCoordinator) Start() {
    // establish connection with reactor and start pinging at set intervals
    var opts []grpc.DialOption
    opts = append(opts,grpc.WithTransportCredentials(insecure.NewCredentials()))
    go r.Monitor(opts)
}

func (r *ReactorCoordinator) Exit() {
    // exit function to eventually allow saving to configs
    fmt.Printf("Reactor %v exiting", r.Id)
}

func (r *ReactorCoordinator) Monitor(opts []grpc.DialOption) {
    retry := 0
    conn, err := grpc.Dial(fmt.Sprintf("%v:%v",r.Ip,r.Port),opts...)
    if err != nil {
        r.Server.Err <-err
    }
    defer conn.Close()
    client := pb.NewMonitoringClient(conn)
    for true {
        req := &pb.SensorStatusRequest{Id:r.Id}
        //time.Sleep(5*time.Second)
        resp, err := client.SensorStatusHandler(context.Background(),req)
        fmt.Println(resp,err)
        ok := true
        if err != nil {
            ok = false
            r.Server.Err <-err
        }
        if ok {
            fmt.Printf("Reactor %v at %v has %v devices connected:\n %v\n",r.Model, r.Ip, len(resp.GetSensors()), resp.GetSensors())
            retry = 0
        } else if retry >= r.MaxAttempts {
            // ran out of attempts to connect; killing
            fmt.Printf("Reactor %v at %v Down! Exiting Coordinator",r.Id,r.Ip)
            r.Exit()
            return
        }else {
            retry++
            fmt.Printf("Reactor %v at %v ping failed, retrying %v time(s)",r.Model,r.Ip, r.MaxAttempts-retry)
        }
        time.Sleep(10 * time.Second)
    }
}